Hi Franii
Are you a teenager or in early 20's?
In my experience, behavior like this is very common for adolescents and young adults. People are often questioning their beliefs, desires, and ideas at this age. In some time, these young adults gain more experience and develop strong desires & wishes.
Some people get past this experience earlier than others ~ and then a small portion of people continue to struggle. Those who continue are commonly referred to as "people pleasers". Being a people pleaser is a problem because your true wants & needs are being stifled inside of you. That can lead to a lot of resentment and anxiety.
I've struggled with this issue myself for quite a while. I have progressed in certain arenas, I can now stand up for what I believe in. In other arenas, I feel lost ~ and have no idea what I truly feel. At least I am making progress, but it takes time. While I don't mimic other people's behavior anymore, I often let them be the decision-makers because my mind is completely blank.
Hope that this helps you, or at least offers some comfort/support to you. Best wishes!